Ulcerative tuberculosis of the skin is a dermatological disease caused by mycobacteria, most often occurs in children and weakened patients against the background of a miliary or systemic tuberculosis lesion. Symptoms of this condition are tubercles and ulcerative rashes, mainly localized around the physiological openings of the body – anal, oral, urethra openings. Diagnosis of ulcerative tuberculosis of the skin is carried out by dermatological examination, microscopic examination of the discharge from ulcers, general examination to identify the active tuberculosis process in the internal organs. In the treatment, the main attention is paid to the elimination of foci in the internal organs, traditional anti-tuberculosis drugs are used for this.
A18.4 Tuberculosis of the skin and subcutaneous tissue
Ulcerative tuberculosis of the skin (secondary tuberculous ulcer) is a rather rare complication of the active tuberculous process in the lungs, urinary system, intestines, observed against the background of a pronounced decrease in the activity of immunity. Most often, this pathology affects children, as well as adults with immunodeficiency of various origins. As with other forms of cutaneous tuberculosis, the cause of the development of this condition is due to infection of the skin tissues with mycobacteria, but in this case, self-infection of the patient plays a significant role.
The development of ulcerative tuberculosis of the skin is a rather formidable complication, since it indicates that the body’s defenses are depleted to a critical level. Such a condition can lead to the dissemination of mycobacteria and even cause death. Therefore, the development of ulcerative tuberculosis of the skin often serves as a reason for urgent hospitalization of the patient in a specialized medical institution and the beginning of intensive anti-tuberculosis therapy.
Mycobacterium tuberculosis becomes the causative agent of any form of tuberculosis lesion, human and bovine varieties of the pathogen are contagious to humans. Despite the fact that mycobacteria are able to colonize almost all tissues of the human body, the skin, by its physico-chemical properties, represents an unfavorable environment for them. Therefore, tuberculosis of the skin is much less common than other forms of this disease, and its appearance indicates a significant weakening of the body. Ulcerative tuberculosis of the skin occurs only in the presence of an active tuberculous focus in the internal organs and with immunodeficiency.
Ulcerative tuberculosis of the skin is most often detected against the background of the active development of mycobacteria in the lungs, intestines, kidneys and urinary tract. At the same time, the pathogen is released in huge quantities into the external environment along with sputum, feces and urine, partially settling on the areas of the skin around the mouth, nostrils, genitals and anus.
With a sharp weakening of the body (both due to the presence of tuberculosis of internal organs, and for other reasons), the introduction and reproduction of mycobacteria in the skin tissues occurs. At first, a typical inflammatory focus appears, as with any other bacterial infection, but all immune responses are weakened. In the future, caseous necrosis occurs in this focus and a characteristic clinical picture of ulcerative tuberculosis of the skin is formed.
An important role in the development of ulcerative tuberculosis of the skin is played by the absence of an allergic reaction of the body to the components of the cell wall of the pathogen. With any other types of tuberculous lesion, it is hypersensitivity reactions that cause many manifestations of the disease – for example, with Bazin’s erythema, almost all symptoms are due to allergies. However, in the case of ulcerative tuberculosis of the skin, the immunity of patients is weakened so much that such active reactions become impossible. This also leaves an imprint on the diagnosis of tuberculosis – widespread methods of its determination, based on hypersensitivity to tuberculin, are negative in such patients.
A constant companion of ulcerative tuberculosis of the skin are the symptoms of the main tuberculous lesion of the internal organs. Depending on the localization of the pathology, it can be a debilitating cough with hemoptysis, profuse sweating at night, abdominal pain, difficult painful urination and other symptoms. The presence of such manifestations indicates an active tuberculosis process, which under certain conditions can lead to the development of ulcerative tuberculosis of the skin. It is also possible to have various mycoses, bacterial infections, symptoms of cancer, which are signs of a severe decline in the activity of the immune system.
The development of ulcerative tuberculosis of the skin itself begins in the areas around the physiological openings of the body – mycobacteria enter the surface of the skin as part of saliva, sputum, feces or urine. First, there are multiple small bumps or nodules of red or purple color, which quickly transform into pustules with a yellowish tinge. With the further progression of ulcerative tuberculosis of the skin, ulcers with raised edges form from pustules, their bottom initially has a bright red color, then becomes covered with gray granulations. Over time, caseous necrosis appears in the form of dirty yellow bumps in the middle of ulcers – specialists in the field of dermatology call these nodules Trel grains.
Subjective symptoms of ulcerative tuberculosis of the skin are reduced to a sharp soreness in the lesions. Patients complain of pain when talking, opening the mouth (with perioral localization), urination and defecation. Other subjective manifestations of ulcerative tuberculosis of the skin are usually not detected or are hardly noticeable against the background of a more severe underlying lesion. Ulcerative erosions of the skin in severe cases can merge with each other, forming a solid large focus. It is possible to develop a secondary bacterial infection, which has an extremely severe course due to weakened immunity.
The diagnosis of ulcerative tuberculosis of the skin is based on the results of dermatological examination of the patient and microscopy of the separated ulcers, the technique of polymerase chain reaction (PCR) can be used to identify mycobacteria. The definition of this disease implies close cooperation between a dermatologist and a phthisiologist, since ulcerative tuberculosis of the skin is always a secondary condition and complication of tuberculosis of internal organs. In addition, it is necessary to conduct a full examination of the patient to determine the causes of immune disorders – in addition to the active tuberculosis process, this may be acquired immunodeficiency syndrome, oncological pathology and other factors.
Microscopic examination (Cyll-Nielsen staining) in the separated mycobacteria, colored red, are determined. Traditional diagnostic methods, such as skin reaction to tuberculin (Mantoux test), in ulcerative tuberculosis of the skin are almost always false negative due to immunosuppression. In this case, it is advisable to replace the tuberculin diagnosis with an enzyme immunoassay, which can confirm the infection of MBT (quantiferon test, T-SPOT.TB).
Treatment is inherently linked to the therapy of the underlying disease. To do this, classic anti–tuberculosis drugs are used – rifampicin, isoniazid and others. Local treatment of dermatological pathology is reduced to the treatment of ulcerative lesions with 50% lactic acid solution and prevention of secondary bacterial infection. In severe cases of ulcerative tuberculosis of the skin, surgical removal of the affected areas is sometimes resorted to. Immunostimulating therapy, proper nutrition, elimination of the causes of immunodeficiency are also necessary.
Prognosis and prevention
The prognosis of ulcerative tuberculosis of the skin is strongly dependent on the course of the main tuberculosis lesion and the state of the patient’s immunity. In children with relatively uncomplicated forms of tuberculosis of the lungs, intestines, kidneys, with proper anti-tuberculosis therapy, both general and dermatological manifestations are eliminated. In cases where the underlying disease is poorly treatable, and immunodeficiency is caused by HIV infection or malignant neoplasm, the prognosis of ulcerative tuberculosis of the skin significantly worsens.
To prevent this condition, tuberculosis patients should monitor the state of their immune system, follow the rules of personal hygiene, wash the genital area, perineum and perianal zone after each urination or act of defecation.